Percutaneous Transluminal Angioplasty Device With Integral Embolic Filter

ABSTRACT

A percutaneous transluminal angioplasty device having an embolic filter mounted to the catheter shaft at a location distal to the angioplasty balloon and downstream from the blockage to capture embolic particles that may be set loose into the blood stream as the angioplasty procedure is performed. The embolic filter is normally collapsed against the catheter shaft to facilitate introduction and withdrawal of the device to and from the operative site. Once the angioplasty balloon is properly positioned, however, means operatively associated with the embolic filter are actuated to erect the filter to operatively position a filter mesh across the lumen of the vessel.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation of U.S. application Ser. No.10/997,803, filed Nov. 24, 2004, now U.S. Pat. No. 8,403,976 issued Mar.26, 2013, which claims benefit of U.S. Provisional Application No.60/560,934, filed Apr. 8, 2004, which applications are hereinincorporated by reference in their entirety.

FIELD OF THE INVENTION

The present invention relates generally to surgical devices and relatesmore specifically to a percutaneous transluminal angioplasty device.

BACKGROUND OF THE INVENTION

The vascular bed supplies a constant flow of oxygen-rich blood to theorgans. If plaque builds up in these vessels, blockages can develop,reducing blood flow to the organs and causing adverse clinical symptoms,up to and including fatality.

Angioplasty is a catheter-based procedure performed by a physician toopen up a blocked vessel and restore blood flow. An entry site isopened, for example in the patient's groin, arm, or hand, and a guidewire and catheter are advanced under fluoroscopic guidance to thelocation of the blockage. A catheter having a small balloon adjacent itsdistal end is advanced under fluoroscopic guidance until the balloonlies within the stenosed region. The balloon is then inflated anddeflated one or more times to expand the stenosed region of the artery.

Since diseased vessels are comprised of a range of material fromearly-stage thrombosis to late-stage calcified plaque, angioplasty canrelease embolic particles downstream from the stenosed location. Theseembolic particles can result in adverse clinical consequences. It hasbeen shown that it is beneficial to trap these embolic particles toprevent them from traveling downstream with blood flow to the capillarybed (e.g., Bairn D S, Wahr D, George B, et al., Randomized Trial of aDistal Embolic Protection Device During Percutaneous Intervention ofSaphenous Vein Aorto-Coronary Bypass Grafts, Circulation 2002;105:1285-90).

In addition to balloon angioplasty, stenoses may also be treated withstents and with mechanical thrombectomy devices. These devices are alsoprone to releasing embolic particles downstream from the stenosedlocation.

There are systems available today that are used to catch these embolicparticles. They are primarily filter systems or occlusion balloonsystems built on a guidewire. These systems have shortcomings related tosimplicity of use and crossing tight lesions with a filter or balloonguidewire that is larger in diameter than the guide wire which isnormally used. These embolic protection guidewires also have flexibilityand stability problems that make the protected angioplasty proceduredifficult in many cases. In the case of saphenous vein grafts, theproblems relate specifically to aorto-ostial lesions, where theguidewire may not be long enough to provide support, or distal veingraft lesions, where there is not enough of a landing zone for thefilter. The latter is a problem as currently available filter systemshave a considerable distance between the treatment balloon and thedistal filter. This distance is a problem not only in distal vein graftlesions, but also in arterial stenoses in which there is a side branchimmediately after the stenosis. In such cases, the filter can often bedeployed only distal to the side branch, thus leaving the side branchunprotected from embolic particles.

SUMMARY

Stated generally, the present invention comprises a percutaneoustransluminal angioplasty device with integral embolic filter. Becausethe filter is integral with the catheter of the angioplasty device,there is no need to insert a separate device into the vessel. Further,proper placement of the angioplasty balloon assures proper placement ofthe embolic filter.

Stated somewhat more specifically, the percutaneous transluminalangioplasty device of the present invention comprises an embolic filtermounted to the catheter shaft at a location distal to the angioplastyballoon, stent, or mechanical thrombectomy device. Thus the filter isdownstream from the blockage and is properly positioned to captureembolic particles that may be set loose into the blood stream as theangioplasty procedure is performed. The embolic filter is normallycollapsed against the catheter shaft to facilitate introduction andwithdrawal of the device to and from the operative site. Once theangioplasty balloon, stent, or mechanical thrombectomy device isproperly positioned, however, means operatively associated with theembolic filter are actuated to erect the filter to position a filtermesh across the lumen of the coronary artery.

In some embodiments the means for erecting the filter comprises aballoon which longitudinally displaces one end of the filter toward theother, causing longitudinal ribs to bow outward, thus erecting thefilter mesh. In other embodiments the means for erecting the filtercomprises a balloon interposed within the proximal and distal ends ofthe filter, whereby inflating the balloon will bias the ribs away fromthe catheter shaft, causing the ribs to bow outwardly to erect thefilter mesh. In still other embodiments the means for erecting thefilter comprises a pull wire attached to one end of the filter, suchthat pulling on the wire longitudinally displaces one end of the filtertoward the other, causing longitudinal ribs to bow outward, thuserecting the filter mesh.

In one embodiment of the invention, a reservoir is provided at thedistal tip of the filter so that when the device collapses forwithdrawal, debris does not get pushed out of the filter.

Additional advantages of the invention will be set forth in part in thedescription which follows, and in part will be obvious from thedescription, or can be learned by practice of the invention. Theadvantages of the invention will be realized and attained by means ofthe elements and combinations particularly pointed out in the appendedclaims. It is to be understood that both the foregoing generaldescription and the following detailed description are exemplary andexplanatory only and are not restrictive of the invention, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate several aspects of the inventionand together with the description, serve to explain the principles ofthe invention.

FIG. 1 is a partial cut away side view of first embodiment of apercutaneous transluminal angioplasty device according to a firstembodiment of the disclosed invention, with the angioplasty balloon andembolism filter in their collapsed positions.

FIG. 2 is a partial cut away side view of the percutaneous transluminalangioplasty device of FIG. 1 showing the angioplasty balloon andembolism filter in their erected positions.

FIG. 3 is a cross sectional view taken along line 3-3 of FIG. 1.

FIG. 4 is a cross sectional view taken along line 4-4 of FIG. 1.

FIG. 5 is a cross sectional view taken along line 5-5 of FIG. 1.

FIG. 6 is a second embodiment of a percutaneous transluminal angioplastydevice according to the present invention, which differs from thepercutaneous transluminal angioplasty of FIGS. 1 and 2 in that theactuation balloon is on the proximal side of the embolic filter, and thefilter erects from a different direction.

FIG. 7 is a view of the percutaneous transluminal angioplasty device ofFIG. 6 showing the angioplasty balloon inflated and the embolic filtererected.

FIG. 8 is a third embodiment of a percutaneous transluminal angioplastydevice and differs from the previously described embodiments in that themeans for erecting the embolic filter is a bellows. FIG. 8 shows theangioplasty balloon and the embolic filter in their collapsed positions.

FIG. 9 IS another view of the percutaneous transluminal angioplastydevice of FIG. 8 showing the angioplasty balloon and the embolic filterin their inflated or raised positions.

FIG. 10 is another embodiment of a percutaneous transluminal angioplastydevice according to the present invention which employs a bellows toraise and lower the embolic filter. The embodiment of FIG. 10 differsfrom the embodiment of FIGS. 8 and 9 in that the bellows is disposed onthe distal end of the filter such that the filter opens from theopposite direction. FIG. 10 shows the angioplasty balloon and theembolic filter in their deflated or collapsed positions.

FIG. 11 is another view of the percutaneous transluminal angioplastydevice of FIG. 10, showing the angioplasty balloon inflated and theembolic filter raised.

FIG. 12 shows still another embodiment of a percutaneous transluminalangioplasty device according to the present invention, in which theballoon interposed between the catheter shaft and the ribs forces theribs upward, thereby causing them to bow into the erected embolicfilter. FIG. 12 shows the device with the angioplasty balloon and theembolic filter in their collapsed or lowered positions.

FIG. 13 is another view of the percutaneous transluminal angioplastydevice of FIG. 12, showing the angioplasty balloon in its inflatedcondition and the embolic filter in its erected condition.

FIG. 14 is another embodiment of a percutaneous transluminal angioplastydevice according to the present invention. This embodiment differs fromthe embodiments of FIGS. 12 and 13 in that the balloon is located at theopposite end of the filter. Nonetheless, when inflated, the balloonforces the ribs away from the shaft and into their accurate positions,thereby raising the embolic filter. FIG. 14 shows the embodiment withthe angioplasty balloon collapsed and the embolic filter retractedagainst the catheter shaft.

FIG. 15 is another view of the embodiment of FIG. 14, showing theangioplasty balloon inflated and the embolic filter erected.

FIG. 16 is still another embodiment of a percutaneous transluminalangioplasty device according to the present invention. This embodimentemploys a pull wire operable from outside the patient which is attachedto a front ring of the embolic filter. When the physician exerts tensionon the wire, the distal ring is displaced proximally, bringing it closerto the proximal ring, thereby causing the ribs to bow outward andthereby erecting the embolic mesh filter. FIG. 16 shows the device withthe angioplasty balloon deflated and the embolic filter collapsedagainst the catheter shaft.

FIG. 17 is a different view of the embodiment of FIG. 16 and shows theangioplasty balloon inflated and the embolic filter erected.

FIG. 18 is another embodiment of a percutaneous transluminal angioplastydevice according to the present invention, showing the angioplastyballoon and the embolic filter in their collapsed conditions.

FIG. 19 is another view of the embodiment of FIG. 18, showing theangioplasty balloon inflated and the embolic filter raised.

FIG. 20 is yet another embodiment of a percutaneous transluminalangioplasty device according to the present invention, showing theangioplasty balloon and the embolic filter in their collapsedconditions.

FIG. 21 is another view of the embodiment of FIG. 20, showing theangioplasty balloon inflated and the embolic filter raised.

FIG. 22 shows a side cut away view of a coronary artery with a stenosis.

FIG. 23 shows the coronary artery of FIG. 20 with a guide wire fedthrough the coronary artery and through the stenosis.

FIG. 24 shows the device of FIG. 1 threaded over the guide wire of FIG.23 and positioned such that the angioplasty balloon is located withinthe stenosis.

FIG. 25 illustrates the angioplasty balloon in its inflated condition toreduce the stenosis, and the embolic filter has been erected to captureany embolic particles that may break loose into the blood stream as aresult of the angioplasty procedure.

FIG. 26 is a partial cut away side view of an embodiment of a device inwhich the angioplasty balloon and embolism filter, shown in theircollapsed positions, are reversed on the catheter shaft for peripheralvascular applications in which blood flows in the opposite direction.

FIG. 27 is a partial cut away side view of the device of FIG. 26 showingthe angioplasty balloon and embolism filter in their erected positions.

FIG. 28 is a side view of an embolism filter according to anotherembodiment of the present invention.

FIG. 29 is a side view of the embolism filter of FIG. 28 with theinflation balloon expanded to erect the embolism filter; filter mesh isshown removed to reveal interior detail.

FIG. 30 is a side view of the embolism filter of FIG. 28 with theinflation balloon deflated; filter mesh is shown removed to revealinterior detail.

FIG. 31 is a side view of the embolism filter of FIG. 28 being retractedinto the forward end of a catheter to collapse the filter; filter meshis shown removed to reveal interior detail.

FIG. 32 is a side view of the embolism filter of FIG. 28, with thefilter expanded and filter mesh in place.

FIG. 33 is a side cutaway view of another embodiment of an angioplastydevice showing an angioplasty balloon in its deflated condition and anembolic filter in a retracted state.

FIG. 34 is a side cutaway view of the angioplasty device of FIG. 33showing the angioplasty balloon inflated and the embolic filter erected.

FIG. 35 is a side view of a further embodiment of an angioplasty devicein which the filter mesh extends beyond the end of the ribs so as toform a sac when the filter is collapsed.

DETAILED DESCRIPTION OF THE DISCLOSED EMBODIMENTS

The present invention can be understood more readily by reference to thefollowing detailed description, examples, drawings, and claims, andtheir previous and following description. However, before the presentdevices, systems, and/or methods are disclosed and described, it is tobe understood that this invention is not limited to the specificdevices, systems, and/or methods disclosed unless otherwise specified,as such can, of course, vary. It is also to be understood that theterminology used herein is for the purpose of describing particularaspects only and is not intended to be limiting.

The following description of the invention is provided as an enablingteaching of the invention in its best, currently known embodiment. Tothis end, those skilled in the relevant art will recognize andappreciate that many changes can be made to the various aspects of theinvention described herein, while still obtaining the beneficial resultsof the present invention. It will also be apparent that some of thedesired benefits of the present invention can be obtained by selectingsome of the features of the present invention without utilizing otherfeatures. Accordingly, those who work in the art will recognize thatmany modifications and adaptations to the present invention are possibleand can even be desirable in certain circumstances and are a part of thepresent invention. Thus, the following description is provided asillustrative of the principles of the present invention and not inlimitation thereof.

As used throughout, the singular forms “a,” “an” and “the” includeplural referents unless the context clearly dictates otherwise. Thus,for example, reference to “lumen” can include two or more such lumensunless the context indicates otherwise.

Ranges can be expressed herein as from “about” one particular value,and/or to “about” another particular value. When such a range isexpressed, another aspect includes from the one particular value and/orto the other particular value. Similarly, when values are expressed asapproximations, by use of the antecedent “about,” it will be understoodthat the particular value forms another aspect. It will be furtherunderstood that the endpoints of each of the ranges are significant bothin relation to the other endpoint, and independently of the otherendpoint.

As used herein, the terms “optional” or “optionally” mean that thesubsequently described event or circumstance can or cannot occur, andthat the description includes instances where said event or circumstanceoccurs and instances where it does not.

The present invention can be understood more readily by reference to thefollowing detailed description of preferred embodiments of the inventionand the examples included therein and to the Figures and their previousand following description.

Referring now to the drawings, FIGS. 1 and 2 illustrate a firstembodiment of a percutaneous transluminal angioplasty device 10according to the present invention. The device 10 comprises an elongatedcatheter 12 having a shaft 14 with a proximal end (not shown) and adistal end 16. Spaced a short distance proximally from the distal end 16of the catheter 12 is an angioplasty balloon 18 of conventional design.In FIG. 1 the angioplasty balloon 18 is shown in a deflated or collapsedcondition. In FIG. 2 the angioplasty balloon 18 is shown in an inflatedcondition.

Located between the angioplasty balloon 18 and the distal tip 14 of thecatheter 12 is a collapsible filter 20. The filter 20 includes aproximal ring portion 22 and a distal ring portion 24. A plurality ofelongated ribs 26 extend generally longitudinally between the proximaland distal rings 22, 24. These ribs can be made of a shape memorymaterial, such as nitinol, and in their baseline position, these ribsare collapsed. A filter mesh 28 overlies the distal portion of the ribs26. In the embodiment of FIGS. 1 and 2, the distal ring 24 is movabletoward and away from the proximal ring 22. As the distal ring 24 movestoward the proximal ring 22, the ribs 26 bow outward. As the ribs 26 bowoutward, the filter mesh 28 overlaying the ribs is erected. FIG. 1 showsthe filter 20 in its collapsed condition, while FIG. 2 shows the filterin its erected condition.

Means 34 are included for erecting and collapsing the filter 20 of thedevice 10 shown in FIGS. 1 and 2. Specifically a balloon 36 has itsdistal end 38 bonded to the shaft 14 of the catheter 12. When the distalring 24 is in its withdrawn position, as shown in FIG. 1, the bulk ofthe balloon 36 is folded forward over the shaft 14 of the catheter 12.When the balloon 36 is inflated, as shown in FIG. 2, the balloon 36expands proximally, pushing the distal ring 24 in a proximal direction,causing the ribs 26 to bow outward and thereby erecting the filter 20.When the balloon 32 is deflated, the shape memory ribs straighten,urging the distal ring 24 in a distal direction and collapsing thefilter 20 close to the shaft 14 of the catheter 12.

FIGS. 3, 4, and 5 show cross sections of the device 10 at variouslocations along its length. Referring first to FIG. 3, the cathetershaft 12 has three lumens: two smaller lumens and a large main lumen.The two smaller lumens are inflation lumens, one lumen 40 for theangioplasty balloon 18, and one lumen 42 for the balloon 36 whichcontrols the filter 20. The larger main lumen 44 is used to receive aguide wire (not shown) over which the device 10 advanced to position thedevice for performing an angioplasty procedure.

Referring now to FIG. 4, this cross section is taken at a locationdistal to the angioplasty balloon 18. Consequently, the angioplastyballoon inflation lumen 40 has terminated and is no longer visible.Thus, FIG. 4 shows only two lumens, the main lumen 44 for receiving theguide wire, and the smaller inflation lumen 42 for the filter balloon36.

Referring now to FIG. 5, this cross section is taken at a locationdistal to the filter balloon 36, and hence only the main lumen 44 isvisible.

FIGS. 6 and 7 show an alternate embodiment of a percutaneoustransluminal angioplasty device 110 according to the present invention.This device is similar to the device 10 previously described, with theexception that the filter 120, in this case, has its distal ring 124fixed, and the proximal ring 122 of the filter 120 is movable toward andaway from the distal ring to cause the ribs 126 to bow outwardly or tostraighten. The balloon 136 is located on the proximal side of thefilter 120 and pushes the proximal ring 122 in a distal direction whenthe balloon 136 is inflated.

Referring now to FIGS. 8 and 9, yet another alternate embodiment ofpercutaneous transluminal angioplasty device 210 is shown. This deviceis similar to the device shown in FIGS. 1 and 2, with the exception thatthe means for erecting the filter 220 is a bellows 236, instead of aballoon. In FIG. 8, the bellows 236 is un-inflated and hence it is in acollapsed condition, permitting the ribs 226 of the filter 220 tostraighten out against the shaft 214 of the catheter 212. In FIG. 9, thebellows 236 has been inflated, pushing the proximal ring 222 in a distaldirection, bowing out the ribs 236 and erecting the filter mesh 238.

FIGS. 10 and 11 illustrate still another embodiment of a percutaneoustransluminal angioplasty device 310. This device is similar to thedevice shown in FIGS. 8 and 9, with the exception that the bellows 336is placed on the distal side of the filter 320. Thus, when the bellows336 is inflated, it moves the distal ring 324 in a proximal directiontoward the proximal ring 322, thereby causing the ribs 326 to bowoutwardly, erecting the filter mesh 338.

FIGS. 12 and 13 depict another embodiment of a percutaneous transluminalangioplasty device 410. In this device the means for erecting the filtercomprises a balloon 436 disposed between the catheter shaft 414 and theribs 426 adjacent the fixed distal ring 424 of the filter 420. When theballoon 436 is inflated, it forces the ribs 426 outward away from thecatheter shaft 414, thereby bowing the ribs and drawing the proximalring 422 of the filter 420 in a distal direction. As the ribs 426 bowoutward, the filter mesh 428 is erected, thereby raising the filter 420.

FIGS. 14 and 15 show a device 510 similar to that shown in FIGS. 12 and13, with the exception that the balloon 536 is placed between thecatheter shaft 512 and the ribs 526 adjacent the proximal ring 522 ofthe filter 520. In the device 510, the distal ring 524 is free to slidealong the catheter shaft 512, such that when the balloon 536 is inflatedand forces the ribs 526 to bow outward, the distal ring 524 slides in aproximal direction, as indicated by the arrow 539 as shown in FIG. 15,permitting the filter 520 to raise.

The embodiment 610 shown in FIGS. 16 and 17 employs a different meansfor erecting the filter 620. In the embodiment 610 a pull wire 650 isused. The pull wire 650 extends through what would formerly have beenused as the filter balloon inflation lumen 644, and the distal end 652of the pull wire 650 is attached to the distal ring 624. When thephysician wishes to raise the filter 620, he exerts a tension on thewire 650, as indicated by the arrow 653, thus drawing the distal ring624 in a proximal direction as indicated by the arrow 655 toward theproximal ring 622. The ribs bow outward, erecting the filter mesh 628 asshown in FIG. 17.

In the device 710 shown in FIGS. 18 and 19, the distal end 752 of a pushwire 750 is attached to the proximal ring 722. Thus when the wire 750 ispushed in the direction indicated by the arrow 753, the proximal ring722 is advanced distally toward the distal ring 724 in the directionindicated by the arrow 755, causing the ribs 726 to bow outward andthereby erecting the filter 720, as shown in FIG. 19.

The device 810 shown in FIGS. 20 and 21 uses a pull wire 850 to erectthe filter 820. The pull wire 850 wraps around an opening 851 in thestationary distal ring 824 and extends rearward toward the proximal ring822 to which the distal end 852 of the pull wire is attached. Thus whentension is exerted on the pull wire 850 in the direction indicated bythe arrow 853, the proximal ring 822 is drawn distally toward the distalring 824 in the direction indicated by the arrow 855, causing the ribs826 to bow outward and thereby erecting the filter 820, as shown in FIG.21.

The operation of the device 10 will now be explained with respect toFIGS. 22-25, and it will be understood that the other devices operate ona substantially the same principles. FIG. 22 shows a vascular structure(e.g., coronary artery, saphenous vein graft, renal artery, carotidartery, superficial femoral artery, etc.) 900 with upper and lower walls902, 904, a branch vessel 905, and a stenosis or blockage 906 caused bythe build-up of plaque or other substances on the arterial walls in sucha way as to narrow the diameter of the arterial lumen, and m theprocess, constrict the flow of blood therethrough.

In FIG. 23, a guide wire 908 has been inserted by the physician, such asthrough the femoral artery, and guided through the vascular system untilthe guide wire passes through the stenosis 906 in the vascular structure900.

Referring now to FIG. 24, the apparatus 10 has been inserted over theguide wire 908 and advanced to a location wherein the angioplastyballoon resides within the stenosis 906. The embolic filter 20 resides afew centimeters distal or downstream from the angioplasty location. InFIG. 24 both the angioplasty balloon and the embolic filter are shown intheir collapsed conditions.

In FIG. 25 the embolic filter 20 has been erected by inflating thefilter balloon 36, causing the distal ring 22 to slide in a proximaldirection along the catheter shaft 12. As the ribs 26 bow outward, themesh filter material 28 supported by the ribs spreads so as to coversubstantially the entire arterial lumen. The angioplasty balloon 18 isnow inflated. As the balloon 18 inflates, it pushes tissue and plaqueforming the stenosis 906 outward, opening the stenosis and possiblyloosening embolic particles in the process. Any such embolic particleswhich get captured in the blood stream will be caught by the embolicfilter 20 and will thereby be prevented from traveling to a locationwhere they can cause clinical damage.

Of interest in FIG. 25 is the close proximity in which the filter 20 iserected relative to the stenosis 906. Despite the short “landing area”between the stenosis 906 and the branch vessel 905, the filter 20 iserected to capture embolic particles upstream of the branch vessel.

When removing the device 10 from the coronary artery, the preferredprocedure is to deflate the angioplasty balloon 18 to first, prior tocollapsing the embolic filter 20. In this way, any embolic particlesthat are broken loose as the angioplasty balloon 18 deflates will becaptured by the filter 20. The embolic filter balloon 20 is thendeflated; permitting the ribs 26 and filter mesh 28 to collapse againstthe shaft 14 of the catheter 12. Any embolic particles captured by themesh 28 are trapped against the shaft 14. The device 10 is thenwithdrawn over the guide wire 908 and removed from the patient's body.

In various peripheral vascular applications, it may be necessary toinsert the catheter against the direction of blood flow (e.g., theaorta). FIGS. 26 and 27 illustrate a device 1000 in which theangioplasty balloon 1018 and the embolic filter 1020 are reversed on theshaft 1014 of the catheter 1012. Thus with the blood flowing within thevessel in the direction indicated by the arrow 1080, the embolic filter1020 will be proximal to the angioplasty balloon 1018 and thuspositioned to capture any embolic particles that may be dislodged by theangioplasty balloon.

While the embodiment 1000 of FIGS. 26 and 27 employs the same method anddevice for erecting the embolic filter as the embodiment 10 of FIGS.1-3, it will be understood that the methods and devices for erecting theembolic filter of other embodiments disclosed above are equallyapplicable to a configuration like the device of embodiment 1000 wherethe angioplasty balloon is positioned between the embolic filter and thetip of the device.

FIGS. 28-32 show still another embodiment of an embolic filter 1120 foruse in conjunction with an angioplasty balloon. FIGS. 28-32 show onlythe embolic filter 1120 and not the angioplasty balloon, but it will beunderstood that the embolic filter is located on the same catheter 1114as the angioplasty balloon in the same manner as the embodimentspreviously disclosed. Further, FIGS. 29-31 show the embolic filter 1120without its filter mesh 1128 for clarity of illustration.

In FIG. 28 the embolic filter 1120 is folded closely against the shaftof the catheter 1112. The ribs 1126 of the filter 1120 extend between aproximal ring portion 1122 and a distal ring portion 1124. The distalring portion 1124 is slidably mounted on the shaft 1114 of the catheter1112, and the proximal ring portion 1122 is fixed with relation to theshaft of the catheter. In FIG. 29 the embolic filter balloon 1136 hasbeen inflated, embolic filter. As the ribs expand, the distal ringportion 1124 slides in the proximal direction, as shown by the arrow1188. Once expanded, the ribs 1126 maintain their shape, such that whenthe embolic filter balloon 1136 is deflated, as shown in FIG. 30, theembolic filter 1120 remains expanded.

To retract the embolic filter 1120, a second, outer catheter 1190 isadvanced over the catheter 1112, as shown in FIG. 31, causing the ribs1126 to collapse as the embolic filter is withdrawn into the forward endof the outer catheter 1190. As the ribs 1126 collapse, the distal ringportion 1124 slides in the distal direction. Once the embolic filter1120 has been completely retracted into the forward end of the outercatheter 1190, the outer and inner catheters are withdrawnsimultaneously.

FIG. 32 shows the embolic filter 1120 with filter mesh 1128 positionedover the ribs 1126.

FIGS. 33 and 34 illustrate a further embodiment of a percutaneousangioplasty device 1210, in which the embolic filter 1220 is located ona different carrier than the angioplasty balloon 1218. Specifically, theangioplasty balloon 1218 is located on an outer catheter 1294, and theembolic filter 1220 is located at the forward end of an inner catheter1295 (the embolic filter 1220 is shown without filter mesh in FIGS. 33and 34 for clarity of illustration.) The outer catheter preferably hasthree lumens, one for inflating the angioplasty balloon 1218, one foraccommodating a guide wire (not shown), and one for receiving the innercatheter 1295 and embolic filter 1220. The inner catheter 1295 isslidably telescopically disposed within the outer catheter 1294. Theribs 1226 of the embolic filter 1220 are formed from a shape-memorymetal such as nitinol and are constructed to normally assume an “open”configuration. When retracted within the forward end of the outercatheter 1294, the ribs 1226 of the embolic filter collapse.

To use the percutaneous angioplasty device 1210, the inner catheter isinserted into the outer catheter so that the embolic filter 1220 iscollapsed within the distal end of the device, as shown in FIG. 33. Theouter and inner catheters 1294, 1295 are inserted together, such asthrough the femoral artery, over a guidewire and advanced through thevascular system to a location wherein the un-inflated angioplastyballoon 1218 resides within the stenosis. Once location of theangioplasty balloon 1218 within the stenosis has been verified bysuitable medical imaging technology, the inner catheter is advanced toprogress the embolic filter 1220 beyond the forward end of the outercatheter 1294. As the embolic filter 1220 is freed from the confines ofthe outer catheter 1294, the ribs assume their expanded configurationand erect the embolic filter. Thereafter the angioplasty balloon 1218may be inflated to treat the stenosis, and any emboli loosened duringthe procedure will be captured by the embolic filter 1220 downstream ofthe stenosis.

When the angioplasty procedure has been completed, the angioplastyballoon 1218 is deflated, and the embolic filter 1220 is withdrawn backinto the forward end of the outer catheter 1294. The outer and innercatheters 1294, 1295 are then withdrawn together from the patient.

In the foregoing embodiment a wire can be substituted for the innercatheter 1295 as a means for carrying the embolic filter 1220.

FIGS. 35 and 36 show an angioplasty device 1310 that is identical to thedevice 10, with the exception that the filter mesh 1328 extends distallybeyond the end of the ribs 1326 and is attached to the distal end of thedistal ring 1324. When the filter 1320 is collapsed, as shown in FIG.36, a sac 1398 is formed which helps contain the embolic particles,thereby minimizing the possibility that the ribs 1326 will squeeze theparticles out of the filter.

In each of the foregoing examples, it will be appreciated that anangioplasty balloon is but one means for relieving a stenosis in avessel. Stents, mechanical thrombectomy devices, or other suitableapparatus may be substituted for the angioplasty balloon and positionedon the catheter at a location proximal to the embolic filter. Thus anyemboli loosened by the stent or mechanical thrombectomy device will becaptured by the embolic filter in the same manner as described abovewith respect to the angioplasty balloon.

While the foregoing disclosed embodiments comprise filter ribs of ashape memory metal such as nitinol, it will be appreciated that similarresults can be obtained by using any suitable resilient material. Theribs would be formed straight, forced open by the balloon, and return totheir normal shape as a result of the resiliency of the structure. Or,in the case of the embodiment of FIGS. 33 and 34, the ribs would beinitially formed in an open position, deformed inwardly to fit withinthe outer catheter, and return to their normal open position whenreleased from the confines of the outer catheter.

Variations in the design of the filter are also contemplated. Forexample, while both ends of the ribs 26 of the filter 20 are mounted torings 22, 24, it will be appreciated that the ends of the ribs at thefixed end of the filter can be secured directly to the catheter shaft.

It will be appreciated that the present invention permits the placementof the embolic filter very close to the means for treating the stenosis.This has the effect of minimizing the “landing area” of the filter andalso permits the protection of side branches, as shown in FIGS. 22-25.

Finally, it will be understood that the foregoing embodiments have beendisclosed by way of example, and that other modifications may occur tothose killed in the art without departing from the scope and spirit ofthe appended claims. Other aspects of the invention will be apparent tothose skilled in the art from consideration of the specification andpractice of the invention disclosed herein. It is intended that thespecification and examples be considered as exemplary only, with a truescope and spirit of the invention being indicated by the followingclaims.

What is claimed is:
 1. A percutaneous transluminal angioplasty device,comprising: an elongated catheter having proximal and distal ends and anouter side wall; an interventional device attached to the catheteradjacent the distal end thereof; a filter attached to the elongatedcatheter between the interventional device and the distal end of thecatheter, the filter being collapsible for insertion of the distal endof the catheter into a blood vessel, and the filter being expandable toan expanded position to capture emboli released into a bloodstream byoperation of the interventional device, wherein the filter comprises: amovable ring portion movably attached to the catheter; a fixed ringportion immovably attached to the catheter such that the movable ringportion is movable relative to the fixed ring portion, wherein themovable ring portion is distal to the fixed ring portion; a plurality ofelongated ribs extending longitudinally between and attached to thefixed and movable ring portions, and a filter mesh overlying a portionof the ribs, wherein the ribs are formed of a shape memory material thaturges the ribs into a collapsed position; wherein the catheter furthercomprises a lumen and a port in communication with the lumen, the portcomprising an aperture in the outer side wall of the catheter locateddistal to the fixed ring portion and proximal to the movable ringportion, and the lumen extending from a location proximate the proximalend of the catheter to the port; and an actuator wire having proximaland distal ends, the actuator wire extending through the lumen of thecatheter, and the distal end of the actuator wire exiting the lumen ofthe catheter through the port, the distal end of the actuator wire beingattached to the movable ring portion; wherein, when the filter is in thecollapsed position, pulling on the proximal end of the wire exerts aforce on the movable ring portion in the proximal direction that movesthe movable ring portion toward the fixed ring portion and causes theribs to bow outward to expand the filter to the expanded position;wherein, when the filter is in the expanded position, releasing tensionon the wire permits the shape memory of the ribs to return the ribs totheir normal, collapsed position, collapsing the filter.
 2. Thepercutaneous transluminal angioplasty device of claim 1, wherein theinterventional device comprises an angioplasty balloon.
 3. Thepercutaneous transluminal angioplasty device of claim 1, wherein theinterventional device comprises a stent.
 4. The percutaneoustransluminal angioplasty device of claim 1, wherein the interventionaldevice comprises a mechanical thrombectomy device.
 5. The percutaneoustransluminal angioplasty device of claim 1, wherein the shape memorymaterial comprises nitinol.
 6. The percutaneous transluminal angioplastydevice of claim 1, wherein filter mesh overlies a distal portion of theribs, and wherein, in the expanded position, the ribs bow outward,radially expanding the filter mesh.
 7. The percutaneous transluminalangioplasty device of claim 1, wherein the filter mesh extends beyondthe ribs in a longitudinal direction relative to the longitudinal axisof the catheter, such that a sac is formed to retain embolic particleswhen the filter is in the collapsed position.
 8. A percutaneoustransluminal angioplasty device, comprising: an elongated catheterhaving proximal and distal ends; an interventional device attached tothe catheter adjacent the distal end thereof; a filter attached to theelongated catheter between the interventional device and the distal endof the catheter, the filter being collapsible for insertion and removalof the distal end of the catheter into a blood vessel, and the filterbeing expandable to an expanded position to capture emboli released intoa bloodstream by operation of the interventional device, wherein thefilter comprises: a movable ring portion movably attached to thecatheter; a fixed ring portion immovably attached to the catheter suchthat the movable ring portion is movable relative to the fixed ringportion; a plurality of elongated ribs extending longitudinally betweenand attached to the fixed and movable ring portions; and a filter meshoverlying a portion of the ribs, wherein the ribs are formed of a shapememory material that urges the ribs into a collapsed position; whereinthe catheter further comprises a lumen extending from a locationproximate the proximal end of the catheter, to a location distal to theinterventional device; and an actuator wire having proximal and distalends, the actuator wire extending through the lumen of the catheter, theproximal end of the actuator wire extending to a location proximate theproximal end of the catheter and the distal end of the actuator wireexiting the lumen through the side wall of the catheter at the locationdistal to the interventional device, the distal end of the actuator wirebeing attached to the movable ring portion; wherein when the filter isin a collapsed condition, manipulating the proximal end of the wireexerts a force on the movable ring portion that moves the movable ringportion toward the fixed ring portion and causes the ribs to bow outwardto the expanded position.
 9. The percutaneous transluminal angioplastydevice of claim 8, wherein the movable ring portion is the distal ringportion.
 10. The percutaneous transluminal angioplasty device of claim9, wherein the distal end of the actuator wire exits the lumen throughthe catheter side wall at a location distal to the proximal ringportion.
 11. The percutaneous transluminal angioplasty device of claim10, wherein the distal end of the actuator wire is operatively connectedto the distal ring portion.
 12. The percutaneous transluminalangioplasty device of claim 11, wherein pulling on the proximal end ofthe actuator wire draws the distal ring portion toward the fixedproximal ring portion.
 13. The percutaneous transluminal angioplastydevice of claim 8, wherein the movable ring portion is the proximal ringportion.
 14. The percutaneous transluminal angioplasty device of claim13, wherein the distal end of the actuator wire exits the lumen throughthe catheter side wall at a location proximal to the proximal ringportion.
 15. The percutaneous transluminal angioplasty device of claim14, wherein the distal end of the actuator wire is operatively connectedto the proximal ring portion.
 16. The percutaneous transluminalangioplasty device of claim 15, wherein pushing on the proximal end ofthe actuator wire moves the proximal ring portion toward the fixeddistal ring portion.
 17. The percutaneous transluminal angioplastydevice of claim 13, wherein the distal end of the actuator wire exitsthe lumen through the catheter side wall at a location distal to theproximal ring portion.
 18. The percutaneous transluminal angioplastydevice of claim 17, wherein the distal end of the actuator wire passesthrough an opening defined by the fixed distal ring portion and thenreturns to be is operatively connected to the proximal ring portion. 17.The percutaneous transluminal angioplasty device of claim 18, whereinpulling on the proximal end of the actuator wire moves the proximal ringportion toward the fixed distal ring portion.
 18. The percutaneoustransluminal angioplasty device of claim 8, wherein the interventionaldevice comprises an angioplasty balloon.
 19. The percutaneoustransluminal angioplasty device of claim 8, wherein the interventionaldevice comprises a stent.
 20. The percutaneous transluminal angioplastydevice of claim 8, wherein the interventional device comprises amechanical thrombectomy device.
 21. The percutaneous transluminalangioplasty device of claim 8, wherein the shape memory materialcomprises nitinol.
 22. The percutaneous transluminal angioplasty deviceof claim 1, wherein filter mesh overlies a distal portion of the ribs,and wherein, in the expanded position, the ribs bow outward, radiallyexpanding the filter mesh.